Electrical-arc welding



smrns PATENT onrion.

JACK GHURCHWABD, NEW YORK, N. Y-., ASSIGNOB T0 WILSON WELDER & METALS GDMPANY, INC., A CORPORATION OF NEW YORK.

ELECTRICAL-ARC WELDING.

No Drawing.

To all whom it may concern:

. Be it known that I, JAcn Gminonwano, a

citizen of. the United States, and a resident of the city, county, and State of New York,

have invented certain. new and useful Improvements in Electrical-Arc Welding, of which the following is a specification.

My invention relates to electric arc welding and one object is to deposit metals which will'be inert to the action of corrosive chemicals such as hot'lye, soda, potash, sulfuric acid and organic chemicals. According to my invention I employ an electrode, which serves ,not only to conduct the current and supply heat to the are, but also supplies the non-corrosive metal to be deposited by the welding process.

.My invention may be applied in many ways. The following examples are given by way of illustrating its application, but I desire it to be understood that they do not limit the scope. of the-invention. One example of the use to which my invention may be put is in the repair of cracks, cavities and the like, which often occur in castiron tanks such as are used,'for example, in various chemical manufacturing industries. These cast-iron tanks are generally made with a high. silicon content and,hitherto,

when such tanks were broken, it was so dif-' ficult to repair them that in many cases 'it was necessary to scrap the tanks. In attempting to repair such tanks, the voids in the tankshave'formerly been filled by welding inthe ordinary-way; but the tanks repaired inithis manner have been extremely short lived owing to the rapid eating away bythe acids, alkali or other chemicals, of the metal'whichhad been deposited. For this reagon, this repair method has been unprofita le.- 1

According to my improved method, the. 1

steel is deposited in the crack or void in the ordinary way but so that the surface of. the weld is below the surface of the inside of the cast-iron tank. An electrode. of noncorrosive metal is then substituted for the original steel electrode and the remainder of the crack or void is completely filled and preferably ".an' additional amount of noncorrosive metal is deposited so as .to entirely cover and overlap the ori alhole in the tank. The tendency "for e ectrolytic action caused bythe union of the two dissimilar metals does not appear to materially afi'ect the weld. In fact on account of the greater solutiontension of the cast-iron, the electromotive force of the electrocouple is of such a character that the non-corrosive metal is actually protected and it has been found in practice that tanks prepared in this manner can be used over again and remain in service for a very considerable length of time. In many cases the surface of the non-corrosive metal becomes coated by the action of the chemicals in the tank, preventing to a large degree the action of the electrolyte or corrosive chemical as the case may be.

Among the non-corrosive metals which may be employed within the spirit of my invention, the following maybe mentioned: nickel, copper, gold and silver. It is also within the spirit of the invention to employ alloys of various kinds as, for example, Monel metal. alloy-a natural combination of about 67% nickel, 28% copper and 5% other metals,

chiefly iron and manganese. It contains no zinc. The nickel and copper bear the same countof the fact that it withstands acids,

alkali, high temperatures and erosive action of hot gases and superheated steam It can be easily cast, forged, rolled, drawn and machined into the form of electrodes.

When welding with an "electrode of Monel metal, it ispreferable, although not necessary, to coat the electrode with lime.

- Patented Apr. 6, 1920. Application filed January 14, 1920. "Serial No. 351,359.

Monel metal is a whitev This may-be accomplished by dipfpin thg milk 0 electrode 'in a saturated solution 0 lime and allowing'it to dig, whereby a thin adherent coating is forme Another use to which I ma apply my non-corrosive electrode is in t hningof metal tanks in various industrial installations where it is impossible to electroplate or otherwise coat the tanks. For example, metal tanks are often situated in out of the way locations where it would be difiicult'or impossible to coat them by electroplating,

. but by the use of my inventlon metal maybe readily depos I the interior of the tanks. Furthermore, it may'often be desiredto build up a non-corrosive tank out of sections, saidsections beited by electric welding upon I do not desire to be limited to the use of any of the metals mentioned herein, but it is to be understood that any electrode of non-corrosive metal may be employed.

I claim:

1. A method of repairing a leaky castiron tank having a crack or cavity therein comprising partially filling the crack or cavity with metal deposited from a steel electrode, and filling the remainder of the crack'or cavity with metal deposited from an electrode of Monel metal.

2. A method of depositing metal upon a plate by electric arc welding which comprises first depositing from a steel electrode, and then depositing from an electrode of a metal which is electropositive to iron.

3. A method of metallic arc Welding which comprises depositing metal from an electrode upon the surface of another metal, the electrode metal being electro-positive to the other metal.

4. The method of electric arc welding which comprises depositing an acid 'resigtan metal from a metallic electrode. A

5 As a new article of manufacture an electrode for metallic arc welding consisting of a non-corrosive metal.

6. As a new article of manufacture an electrode for electric arc welding for producing non-corrosive deposits consisting of Monel metal. 1

7. As a new article of manufacture an electrode for electric arc welding for ro- (lacing non-corrosive welds containing f om 60-67% nickel and 28-40% copper.

8. As a new article of manufacture an electrode for electric arc welding for producing non-corrosive welds, consisting of Monel metal with a coating of lime.

9. An electrode for electric arc weldin consisting of a metal which will withstan acids, alkali, high temperatures and the erosive action of hot gases and superheated steam. v

In testimony whereof I have afiixed my signature to this specification.

JACK CHURCHWARD. 

